Take a piece of plywood and measure out 2 pieces that are 5 feet long and 2 1/2 feet wide each for the top and bottom of your wall unit. Cut these out.
Measure and cut out 2 similar pieces that are 6 feet long and 2 1/2 feet wide. These are the sides.
Cut 3 pieces that are 4 feet 10 1/2 inches long and 2 1/2 feet wide each for the shelves.
Cut 2 similar pieces measuring 2 1/2 feet long and 6 inches wide. These are the spacers between the shelves.
Sand any rough edges on all cut pieces. Apply wood stain or paint of your choice and allow to dry.
Take one of the pieces for the bottom of the unit and the two 6 feet long sides. Screw a side section to both 2 1/2 feet ends of the bottom piece so that the sides are sitting on top of the bottom. Pass the screw through the bottom piece on each end into the side sections. Use 3 screws on each end. You now have 3 sides of a rectangle.
Screw one of the 2 1/2 feet long and 6 inch wide shelf dividers in the center of the bottom piece on the same surface as the sides. Screw the 2 1/2 feet long edge to the bottom piece so it runs parallel to the sides. Drive 2 screws up through the bottom into this piece.
Place one of the 4 feet 10 1/2 inch long sections in between the sides on top of the shelf divider. Screw this piece in by driving 3 screws through the sides on each end into it. The shelf divider will secure itself at the top.
Take the other shelf divider and sit on the shelf just installed so it is above the divider on the bottom shelf. Place another 4 feet 10 1/2 long section in between the sides on top of the shelf divider and screw to the sides. The pressure of both shelves will hold that shelf divider in place. You can use some wood glue on this divider before installing the shelf if you want.
Screw the remaining 5 feet long piece across the top of your wall unit using 3 screws on each end. Drive the screws down through the top into the sides.
Take the remaining 4 feet 10 1/2 inch long section and screw it in between the sides of the wall unit 9 inches below the top for the media shelf above the TV. Use 4 screws on each end for this piece and drive them through the sides into it.
Stand your wall unit up with the 4 shelf compartments on the bottom. Place the TV in the large space above the shelves.